Sighting device with microspheres

ABSTRACT

An aiming sight has a base, at least one light emitting element on the base, and a clear cover over the light emitting element. The light emitting element is made of light gathering plastic combined with self-luminous microspheres. When ambient light is present, the light emitting element functions as a light gathering rod that emits light from the back end. When no light is present, the light emitting element is self-luminous.

This application claims the benefit under 35 U.S.C. §119(e) of the U.S. provisional patent application No. 61/259,270 filed Nov. 9, 2009.

TECHNICAL FIELD

The present invention relates to aiming sights and more particularly to sighting devices with self-luminous microspheres for bright light, low light and dark conditions.

BACKGROUND ART

Modern firearms are inherently very accurate. The ability to shoot accurately depends on accurate pointing or aiming, and often requires rapid acquisition of the target. Known sights commonly have a front sight in the form of a small bead sight near the muzzle or front of the firearm barrel. Such sights can also have a rear sight near the breach or rear of the firearm barrel.

Conventional bead sights have several shortcomings. Bead sights are difficult to see in low light conditions and against dark backgrounds. One improvement to front sights relative to the bead sight is the use of a small artificial light source to replace the bead sight. The light source can be electrical or photo chemical. Front sights with artificial light sources are relatively complex and require periodic replacement of the light or power source.

Another improvement is the use of a light-gathering tube or rod, generally of a colored plastic material, to replace the bead sight. Such light-gathering tubes have a length many times the cross sectional dimension, and thereby have a peripheral surface area much greater than the end area. Light is absorbed through the peripheral surface and emitted through the end of the tube. A front sight with a light-gathering tube is easily seen in bright light and low light conditions, and against a dark background. However, such sights are not readily visible in dark conditions.

A further improvement is the combination of a light-gathering tube or rod with a radioluminescent capsule at or in the forward end of the light-gathering rod. In daylight and low light conditions, the light-gathering tube gathers ambient light and directs the light rearwardly, providing a bright dot for aiming. In the dark, the light from the radioluminescent capsule is guided through the light-gathering tube to provide a bright dot for aiming. The radioluminescent capsule is generally a short glass tube that is coated on the inside with a phosphor and contains a radioactive gas such as tritium. Firearm sights can experience high shock loads from firing of the weapon. The radioluminescent capsules must be carefully mounted to prevent breakage and escape of the radioactive gas. Another problem with known devices of this kind is migration or separation of the radioluminescent capsule from the light-gathering tube due to adhesive failure.

U.S. Pat. No. 4,677,008 to Webb and U.S. Patent Publication No. 20070200074 to Kohnen each disclose radioluminescent microspheres. Webb and Kohnen both disclose that the microspheres can be “disposed on a surface to form signs, markers, indicators and the like” and “disposed in a transparent binder to form a luminous paint”.

DISCLOSURE OF THE INVENTION

A sighting device includes a base, an elongated light emitting element, mounted on the base and a cover. The light emitting element has a periphery through which light is absorbed and a rearwardly facing back end through which light is emitted. A plurality of light emitting microspheres are embedded in the light emitting element. The light emitting element is a light gathering rod when ambient light is present and is self-luminous when no light is present.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of this invention are described in connection with the accompanying drawings that bear similar reference numerals in which:

FIG. 1 is a perspective view of a front sight embodying features of the present invention.

FIG. 2 is an exploded, partially cutaway view of the front sight of FIG. 1.

FIG. 3 is a perspective view of a rear sight embodying features of the present invention.

FIG. 4 is an exploded, partially cutaway view of the rear sight of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, a front sight 11 embodying features of the present invention includes a base 14, a light emitting element 15 and a cover 16. The base 14 has a lower mounting portion 18 and an upper element holder 19 attached on top of the mounting portion 18. The base 14 is preferably made of metal or an opaque plastic. The mounting portion 18 shown is sized and shaped to mount near the muzzle of a handgun. Other configurations of the mounting portion 18 can be used for other weapons.

Describing the specific embodiments herein chosen for illustrating the invention, certain terminology is used which will be recognized as being employed for convenience and having no limiting significance. For example, the terms “front”, “back”, “right”, “left” “vertical”, “horizontal, “lateral”, “longitudinal”, “upper” and “lower” refer to the illustrated embodiment in its normal position of use. Further, all of the terminology above-defined includes derivatives of the word specifically mentioned and words of similar import.

The element holder 19 has an elongated, rectangular bottom portion 21 extending from a front end 22 to a spaced back end 23. A front wall 25 projects upwardly from the bottom portion 21 at the front end 22, and a back wall 26 projects upwardly from the bottom portion 21 at the back end 23. The bottom portion 21 has an upwardly facing top surface 27 with an upwardly opening element channel 28 that extends from the front wall 25 to the back wall 26. A front element aperture 30 extends through the front wall 25 and a back element aperture 31 extends through the back wall 26. The front element aperture 30, the element channel 28 and the back element aperture 31 are aligned with each other, and sized and shaped to the receive the light emitting element 15.

The light emitting element 15 shown is generally an elongated cylinder with a front end 33, a spaced back end 34, an enlarged back section 35 at the back end 34, and a peripheral surface 36. The peripheral surface 36 is preferably smooth and polished to receive light. The back end 34 is preferably flat or convex, and textured to emit light rearwardly. A groove 37 extends around the peripheral surface 36 near the front end 33. The light emitting element 15 shown is injection molded and therefore can made in any selected shape. The light emitting element 15 can also be extruded, but extrusion limits the shapes available.

The light emitting element 15 is made of a mixture of translucent plastic and light emitting microspheres 40. The plastic is generally a bright color such as green, crimson, yellow or orange. The microspheres 40 are generally evenly and randomly distributed throughout the light emitting element 15. The microspheres 40 are generally hollow microspheres of glass or polymer containing a radioactive gas, such as tritium, and particles of a phosphor that emit light in response to radioactive decay in the gas.

Ambient light is absorbed through the peripheral surface 36 and emitted through the back end 34. Light from the microspheres 40 is also emitted through the back end 34, illuminating the back end 34 even when little or no ambient light is present. The concentration or relative volume of the microspheres 40 in the light emitting element 15 can be selected to tailor the relative brightness of the back end 34 between bright and dark light conditions.

The cover 16 is made of a clear plastic and is an elongated, partial cylinder shape sized to extend from the front wall 25 to the back wall 26. The cover 16 has an internal channel 41 sized to receive the light emitting element 15. The cover 16 is preferably molded over the base 14 after the light emitting element 15 is assembled to the base 14, so that the cover 16 fills the groove 37 and locks the light emitting element 15 to the base 14. In addition to retaining the light emitting element 15 to the base 14, the cover 16 also protects the light emitting element 15 from external damage.

Referring now to FIGS. 3 and 4, a rear sight 44 embodying features of the present invention includes a base 46, a pair of light emitting elements 47 and a cover 48 for each light emitting element 47. The base 46 includes a lower mounting portion 51 and an upper body 52 attached on top of the mounting portion 51. The base 14 is preferably made of metal or an opaque plastic. The mounting portion 51 shown is sized and shaped to mount near the breech of a handgun. Other configurations of the mounting portion 51 can be used for other weapons.

The body 52 includes a generally square lower section 54 and a pair of spaced element holders 55 that project upwardly from the lower section 54. The lower section 54 defines the bottom of a sight channel 56, and the element holders 55 define the sides of the sight channel 56.

Each element holder 55 has an elongated, intermediate section 58 on the lower section 54. The intermediate section 58 extends from a front end 59 to a spaced back end 60. A back wall 62 projects upwardly from the intermediate section 58 at the back end 60. The intermediate section 58 has an upwardly facing top surface 63 with an upwardly opening element channel 64 that extends forwardly from the back wall 62. A back element aperture 66 extends through the back wall 62. The element channel 64 and the back element aperture 66 are aligned with each other. An intermediate element aperture 67 extends downwardly from the element channel 64 into the intermediate section 58. The element channel 64, the back element aperture 66 and the intermediate element aperture 67 are sized and shaped to the receive the light emitting element 47.

The light emitting element 47 shown has an elongated cylindrical first section 69 with a front end 70 and a spaced back end 71, and a cylindrical second section 73 that projects transversely from the first section 69 intermediate the first and second ends 70 and 71. The first section 69 has a peripheral surface 74 that is preferably smooth and polished to receive light. The back end 71 is preferably flat or convex, and textured to emit light rearwardly. The light emitting element 47 shown is injection molded and therefore can made in any selected shape. The light emitting element 47 can also be extruded, but extrusion limits the shapes available. The first section 69 fits into the element channel 64 and the back element aperture 66, with the second section 73 projecting downwardly into the intermediate element aperture 67.

The light emitting element 47 is made of a mixture of translucent plastic and light emitting microspheres 40. The plastic is generally a bright color such as green, crimson, yellow or orange. The microspheres 40 are generally evenly and randomly distributed throughout the light emitting element 47.

Ambient light is absorbed through the peripheral surface 74 and emitted through the back end 71. Light from the microspheres 40 is also emitted through the back end 71, illuminating the back end 71 even when little or no ambient light is present. The concentration or relative volume of the microspheres 40 in the light emitting element 47 can be selected to tailor the relative brightness of the back end 71 between bright and dark light conditions.

Each cover 48 is made of a clear plastic and is sized and shaped to fit over the top surface 63 of the intermediate section 58 of the element holder 55 and has an internal channel 76 sized to fit over the light emitting element 47. The cover 48 is preferably molded over the base 46 after the light emitting element 47 is assembled to the base 46, so that the cover 48 retains the light emitting element 47 to the base 46. In addition to retaining the light emitting element 47 to the base 46, the cover 48 also protects the light emitting element 47 from external damage.

When the front sight 11 and rear sight 44 are mounted on a firearm, the user aligns the front sight 11 in the sight channel 56 of the rear sight 44. The light emitting elements 15 and 47 function as light gathering rods or tubes during bright light and low light conditions, and as self-luminous light source in dark conditions. The microspheres are capable of withstanding 5,000 psi of crush force. Embedding the microspheres 40 into the light emitting elements 15 and 47 eliminates the adhesive failure problems associated with devices that use a separate self-luminous capsule, and eliminates the risk of breakage of a separate self-luminous capsule. Eliminating the separate self-luminous capsule allows the front and rear sights 11 and 44 to have shorter bases 14 and 46.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof. 

1. A sighting device for a weapon comprising: a base having a lower mounting portion for attachment to said weapon and an upper element holder, and an elongated, translucent light emitting element sized and shaped to mount on said element holder, said light emitting element having a front end, a spaced back end, a light gathering peripheral surface extending between said front and back ends, and a plurality of light emitting microspheres distributed inside said light emitting element between said front and back ends, said back end being shaped to emit light gathered by said peripheral surface and light emitted by said microspheres, whereby said back end is visible for aiming said weapon in bright light, low light and dark conditions.
 2. The sighting device as set forth in claim 1 wherein said light emitting element is made of a mixture of translucent plastic and said microspheres.
 3. The sighting device as set forth in claim 2 wherein said plastic is a bright color and is one of green, crimson, yellow and orange.
 4. The sighting device as set forth in claim 1 wherein said microspheres are generally evenly and randomly distributed throughout said light emitting element.
 5. The sighting device as set forth in claim 1 including a clear cover attached to said base, said cover extending over said light emitting element.
 6. The sighting device as set forth in claim 1 wherein said back end of said light emitting element is textured to emit light rearwardly.
 7. The sighting device as set forth in claim 1 wherein said microspheres contain a radioactive gas and particles of a phosphor that emit light in response to radioactive decay in said gas.
 8. The sighting device as set forth in claim 7 wherein said gas is tritium.
 9. The sighting device as set forth in claim 1: wherein said base includes a pair of laterally spaced element holders and a sight channel between said element holders, and said mounting portion is sized and shaped to mount near a breech of a firearm, and including a light emitting element for each said element holder, whereby a user sights between said light emitting elements.
 10. The sighting device as set forth in claim 1 wherein said light emitting element is injection molded, whereby said light emitting element can be made in any selected shape.
 11. A sighting device for a weapon comprising: a base having a lower mounting portion for attachment to said weapon and an upper element holder, an elongated light emitting element sized and shaped to mount on said element holder, said light emitting element having a front end, a spaced back end, a light gathering peripheral surface extending between said front and back ends, and a plurality of light emitting microspheres generally evenly and randomly distributed throughout said light emitting element, said back end being textured and shaped to emit light gathered by said peripheral surface and light emitted by said microspheres, said light emitting element being injection molded and made of a mixture of brightly colored, translucent plastic and said microspheres, said microspheres containing tritium gas and particles of a phosphor that emit light in response to radioactive decay in said tritium, and a clear cover attached to said base, said cover extending over said light emitting element, whereby said back end is visible for aiming said weapon in bright light, low light and dark conditions.
 12. A sighting device for a weapon comprising: a base having a lower mounting portion for attachment to said weapon, a pair of laterally spaced upper element holders and a sight channel between said element holders, an elongated light emitting element for each said element holder sized and shaped to mount on said element holder, each said light emitting element having a front end, a spaced back end, a light gathering peripheral surface extending between said front and back ends, and a plurality of light emitting microspheres generally evenly and randomly distributed throughout said light emitting element, said back end being textured and shaped to emit light gathered by said peripheral surface and light emitted by said microspheres, each said light emitting element being injection molded and made of a mixture of brightly colored, translucent plastic and said microspheres, said microspheres containing tritium gas and particles of a phosphor that emit light in response to radioactive decay in said tritium, and a clear cover for each said light emitting element, each said cover being attached to said base and extending over said light emitting element, whereby said back end is visible for aiming said weapon in bright light, low light and dark conditions. 